1. Field of the Invention
The invention relates to a method and apparatus for the compressive treatment of web material in order to mechanically impart pre-shrinkage and stretch properties to the material.
2. Description of the Related Art
There are a number of different machines and methods available for effecting a compressive force on thread interlaced web material in order to impart pre-shrinkage properties. In my previous patents, U.S. Pats. Nos. 4,363,161 and 4,447,938, I disclosed such methods and apparatus.
The method disclosed in U.S. Pat. No. 4,363,161 comprises forcing a fibrous thread interlaced web material into a stuffing chamber where the stuffing chamber is formed by a confining means having an apex and two movable surfaces with the apex extending in part between the surfaces. One of the surfaces is moved with respect to the confining means in a direction toward the stuffing chamber at a particular speed in order to feed a web of material into the chamber. The second movable surface moves in a direction substantially opposite to the direction of movement of the first surface and at a slower speed to move compressed material out of the stuffing chamber.
U.S. Pat. No. 4,447,938 discloses a similar method and apparatus. However, it includes the provision of an impact blade. The impact blade is used when greater shrinkage control is desired. In this situation, the fabric must be compressed to a greater extent. Under high fabric compression forces, the fabric tends to be forced into the nip area between the moving surfaces instead of around the apex. The impact blade prevents this and directs the fabric around the apex.